Filter



Oct. 14, 1952 L. 1 MooRE l FILTER Filed April 19. 1948 INVENTOR. LAURE/VCE l.. MOORE IML@ A TTORNEY Patented Oct. 14, 1952 FILTER Laurence L. Moore, Oakland, Calif., assignor to l Winslow EngneeringCo., Oakland, Calif., a

partnership Application April 19, 1948, Serial No. 21,900 j I (ci. 21o-148) 4 Claims.

yThis invention relates to improvements in an apparatus for oil iiltering. More particularly, this invention relates to an .improved oil-ltering cartridge. Still more specically, the invention relates to an improvement in a knittedsock type of oil filtering cartridge in which a stiiening member of porous or perforated, substantially inextensible material, is employed to prolong the life and enhance the eiiiciency of the cartridge.

Knitted sock cartridges such as described in the patent to myself and Charles A. Winslow, No. 2,314,640, have proved very satisfactory in most respects. However, after some of the largest sizes of these lter cartridges have been in heavy duty use in certain types of service, they sag down when an excessive weight of sludge is collected in the cartridge. When the cartridge is loaded beyond normal dirt capacity and used in service where vibration or jolting tends to jar and sag the cartridge down inthe filter, there is danger of the cartridge swelling and shortening, thus losing its end seal. In this case, the oil being flltered could by-pass the top of the filter and thereby ilow to the iilter outlet without passing through the lter material.

Various means havebeen employed to correct this problem with knitted sock cartridges, but due to the nature of the lter material and the flexibility of the knitted covering, in some cases, the

have not been entirely successful. l f

Substitutes for knitted material have been used at various times, but have not proven satisfactory. Woven materialinterferes with the free flow of liquid, unless the openings between thethreads are so wide that the looselyv woven material develops the same objectionable characteristics as knitted materials. Among. other materials used to form a casing for lter media haveb'een perforated cardboard, breboard, etc. These casings, While possessed of suiiicient rigidity to resist deformation, had a limited iilter capacity. This limited capacity was due to the insuicient number and small size of the perforationswhich were allowable in the tubular cardboard sections of the filter. The size of the openings was aparticularly undesirable shortcoming because it could not be altered very muchwithout dangerof losing lter media. Thus, the dilemma has been the choice between the advantages of a free-flowing knitted outer sock which can sag, and a cartridge which will not sag but is also not free-ilowing nor possessed of the other-advantages of a knitted-sock type of cartridge.

One object ofv this invention :toprovideav sock type filter which will` not become deformed solongasitisinuse. u

Another object of the invention is to provide a sock type lter in which there is incorporated a stifiening member which does `not interfere, with the free-flowing characteristics of the filter.

Another object of the invention is to provide a free-owing stiff cartridge with satisfactorysediment-removing characteristics.v y

Another object of the invention is to provide a sock-type lter having a double outer layer ofv knitted fabric in between which isa layerfof stiff, porous, or perforated, substantially inextensible material. l,

' Other 'objects and advantages oi the invention will appear from ther coursevof therfollowin'gdescription, g-iven as a preferred embodiment in conformity with U. S. Revised LStatutes'Section 4888, without intent to limit the invention other.- wise than as required by the claims.-v f i, Y

Referring to the accompanying drawing:y

Fig. 1 is a vertical sectional view-illustrating the rst stages of stretching the flexible knitted material over and into acasing containing-the reinforcingr girdle, for loading the `iilteringredients in the properform; f 4 l Fig.,2 is a vertical sectional view of .theselcond stage wherein the ltering and purifying ingredients are shown compressed in the porous'flex'- ible knitted casing which is heldin proper form by a metal container and central stud arrangement; Y

Fig. 3 is a vertical sectional View of .thefnovel element illustrating the third stage' of construction showing the knitted casing.'about to be forced into the second foldingoperationand locked inplace with the wire coil spacer, with the reinforcing fluid-permeable girdle inposition between the two outer plies ofthe cartridge; i

Fig. 4 is a vertical sectional view of the finished element inits preferred form; andv I Fig. 5 is a horizontal sectional view'of the novel element taken on the line Vf-V of Fig. fi. p

In general the product of this invention Vprovides a free-flowing sediment-removing sock-type nlter cartridge of .the typev having, a ,tworply knitted casing, and comprises the combination with this cartridgeof a stiffeninggirdle between the two outer layers, the girdle being 'constructed of Huid-permeable, substantially inextensible material. The improvedconstruction is.preferably formed by; `a method comprising the steps of: 113), compacting a predetermined quantity iof :agsuitable filtering material intoa tubular fabric casing which is capable of expanding,transverselywhile maintaining ahollow space centrally through the cartridge, the iilled portionof,` the ,casingbeing surrounded by a permeableand4 substantially ginment to a lesser diameter than the inside diameter j,

vof the coiled spacer spring l2 so that the element I0 will seal on both ends of the hollow outlet tube of a lter, when the cartridge I0 is installed in a lter housing.

I claim:

1. In a'fllter cartridge of the type in' which there is a core of fibrous ltering material having an aperture extending therethrough, annular retainer members positioned adj acentthe respective ends of said core aperture, a unitary tubular sheath of extensible material encircling said core in a plurality of continuous toroidal convolutions and passing through said core aperture, and means within said core aperture for holding said sheath in engagement with said annular retaining members; the combination therewith of a fiuid-permeable, substantially inextensible, cylindrical girdle between two of the outside convolutions of said sheath.

2. The combination claimed in claim 1, in which said girdle is made from substantially inextensible woven cloth.

3. The combination claimed in claim 1ln which said girdle is made from cardboard having perforations in its circumference.

4. The combination claimed in claim 1, in which said girdle is made from wire screen.

LAURENCE L. MOORE.

REFERENCES CITED l' The following references are of record in the le of this patent:

UNITED STATES PATENTS y2,511,292 Myers June'13, 1950 

